Memo to Rep. Bob Brady: Congress can’t legislate civility.

The attempted assassination of Rep. Gabrielle Giffords really did rattle Washington. It took an entire day before someone reacted by proposing new, horrible legislation.

That someone is Rep. Bob Brady D-Pa., who told CNN Sunday that he’d draft a bill making it a crime to use words or images that looked violent or threatening to public officials. “You can’t put bull’s eyes or crosshairs on a United States congressman or a federal official,” Brady said. “The rhetoric is just ramped up so negatively, so high, that we have got to shut this down.” The solution: Expand Title 18, Section 871 of the U.S. Code so that more public servants would be protected from written threats.

Would it be rude to point out the problem with this? There’s no evidence—none—that violent pictures or words inspired the violence in Arizona. In its complaint charging Jared Lee Loughner with murder and attempted assassination, the FBI found a letter confirming Loughner’s attendance at a 2007 event with Giffords (he’d told a classmate that he found her to be “stupid”). That predates, by three years, Sarah Palin’s election map of 20 congressional districts ripe for Republican takeover, marked with white and red targets. And Palin’s map was the target—if I’m still allowed to say that—of Brady’s bill. (“Someone is feeling a little guilty,” he told CNN, asking us to read “Palin” between the lines.)

This is Brady’s idea, but he’s not alone in obsessing over it. In the aftermath of the Tucson shootings, liberals have scoured the Internet for evidence of Republicans talking violently, and conservatives have responded by finding Democratic maps festooned with targets. Time magazine pondered a “new era of political correctness,” because both parties were guilty—why, in 2008, candidate Barack Obama even riffed off the never-bring-a-knife-to-a-gunfight line from The Untouchables!

I’ll go ahead and predict that the New Era of Political Correctness will be shorter-lived than the “death of irony” we witnessed after 9/11. Brady’s proposed legislation is half unenforceable and half redundant. Threats against public officials are already illegal. A year ago, a Pennsylvania man was arrested because his interminable YouTube rants veered into threats against Eric Cantor, who’s now the House majority leader.

Loughner didn’t make any YouTube threats. Based on what we know from fellow students, he was becoming increasingly odd, asking “random, weird questions that didn’t go together,” but he never talked about buying a gun. He kept his assassination plan locked in a safe, not posted on Facebook.

I can see why Brady wants to pass this bill. I can see why Palin’s Web aide, Rebecca Mansour, has tried to convince a doubting world that the targets on Palin’s map were actually “surveying symbols.” This is a political story, and they need a political fix for it. They at least need to do something that feels like a political fix.

But there just isn’t any fix for this. We are starting to learn what Loughner actually thought about politics. In one of his Web videos, he asked “What’s government if words don’t have meaning?” A friend of Loughner’s told the AP on Sunday that the alleged killer “did not like government officials, how they spoke. Like they were just trying to cover up some conspiracy.”

That’s political paranoia, which is not the same thing as anger against politicians. We’re in a boom period for paranoia right now. One example: After Obama was elected president, there was a run on ammunition, because gun owners worried he would ban weapons and gun sellers fed into the worry. In its May 2009 newsletter, the Arizona Civil Defense League—a gun-rights group that successfully lobbied for the state’s open-carry law—listed the possible ways national Democrats could restrict gun rights, illustrating this with an Obama “Yes We Can” sticker blotting out the Second Amendment. None of the restrictions they worried about actually happened.

If you distrust the government, you’ve got good instincts. You can also be wildly misled. Conspiracy theories are interesting, and doomsday scenarios are clarifying, and on the Web it’s easier than ever to find them. And more and more, if you are worried about one-world government or a North American superhighway, you can hear about them on some of the mainstream media you listen to—and they take on gravitas when they’re mixed in with the rest of the stories.

If you want the harder stuff, that’s easy to get, too. Timothy McVeigh had to hunt for his copy of the Turner Diaries. In five minutes on his parents’ computer, a paranoid person could obtain that book; the “Protocols of the Elders of Zion”; any number of fire-has-never-melted steel documentaries about 9/11; and David Icke’s theories about the shapeshifting Lizards who control the world.

Loughner’s particular brand of paranoia was incoherent. “I know who’s listening: Government Officials, and the People,” Loughner wrote in one of his YouTube essays. “Nearly all the people, who don’t know this accurate information of a new currency, aren’t aware of mind control and brainwash methods. If I have my civil rights, then this message wouldn’t have happen[ed].” But he was using his civil rights to publish a video essay; if government officials heard him, it’s because they clicked on it.

On Saturday, before we knew much about Loughner, an Arizona Tea Party activist told me the incident had made him think about how he talked. “Should I talk differently when I describe the Founders and compare what we’re facing to what they faced?” Patrick Beck asked. “Could somebody imply that I’m calling for a revolution?”

I’ve thought about that as I read more about Loughner. Beck was thinking about how to calibrate what he said so that the craziest person in the room wouldn’t take it the wrong way. This is undoubtedly what Rebecca Mansour wished she’d done when Democrats like Giffords started complaining about the map of targeted seats. And I suppose that’s what Bob Brady wants to do, with the force of federal law and prison sentences. But what’s the long game? If someone like Jared Loughner wants to develop bizarre ideas about government based on obscure online theories—or based on nothing at all—no amount of civil dialogue will prevent it.